Heat Pump Running Constantly – Is It Normal?

Introduction

If you’ve recently had a heat pump installed, it can feel worrying when it seems to be running all the time.

Many homeowners expect it to behave like a gas boiler — switching on, heating quickly, then switching off.

A heat pump works differently.

In many cases, running for long periods is completely normal. But sometimes it can indicate a setup issue.

Here’s how to tell the difference.

1. Heat Pumps Are Designed To Run Longer

Unlike boilers, heat pumps work at lower flow temperatures.

Instead of blasting heat into radiators at 70°C, they often run between 35–45°C.

That means they run for longer periods to maintain steady room temperatures.

This is called “low and slow” heating — and it’s usually more efficient.

If your home is warm and comfortable, constant running is not automatically a problem.

2. It’s Often Normal In The First Winter

New systems sometimes run longer in colder weather because:

• The building fabric is still stabilising 

• Settings may be conservative

• Weather compensation hasn’t been fine-tuned 

First winters are often about small adjustments.

3. Check Your Flow Temperature

If your flow temperature is set too high (e.g. 55–65°C), the system may cycle inefficiently.

If it’s set too low for the radiator size, it may struggle and run continuously without reaching setpoint.

Typical ranges:

• Underfloor heating: 30–40°C

• Radiator systems: 35–50°C (depending on design)

If it’s constantly running but the house never quite gets warm, that’s when to investigate further.

4. Weather Compensation Settings

Modern systems adjust flow temperature based on outdoor temperature.

If the curve is too flat, the system may run constantly without building enough heat.

If it’s too aggressive, it may cycle.

A correct weather compensation setup is key to balanced performance.

5. When It’s A Problem

Running constantly may need attention if:

• The house isn’t reaching the desired temperature 

• Electricity usage is unusually high

• The backup heater is operating frequently

• The system is short-cycling 

These are commissioning or design indicators.

Final Thoughts

A heat pump isn’t “fit and forget” — especially in its first winter.

Long run times are often completely normal and can even be a sign of efficient low-temperature operation.

However, if your system is running constantly and:

• The house isn’t reaching the desired temperature

• Electricity usage is unusually high

• The backup heater is operating frequently

• The system is short-cycling

Then it’s worth reviewing the setup properly.

If your electricity bills are higher than expected, read:
Why Is My Heat Pump Using So Much Electricity? 

Flow temperature settings may also be a factor.
See: What Flow Temperature Should My Heat Pump Run At?

If you'd like a structured review of your system performance, you can book a heat pump consultation here.